What's the difference between well/poorly expressed and grammatical/ungrammatical? If I said, "I gave him a good advice," what would you call it?
I've found the following examples with obligation:
1. "Board members of the Bundesbank are under obligation to show restraint in their political activities." (The New York Times)
2. "Whatever Mr. Bush's choice, Mr. Dukakis said, Mr. Gore is still under obligation to pick someone who could step into the job of president." (The New York Times)
3. "At some point, he began to feel that he was under an obligation to marry her." (The New Yorker)
4. "He is under an obligation to manage the business so that profits are maximised." (The Guardian - Opinion)
I can't understand why obligation is uncountable in the first two. Are they well or poorly expressed?